Process for purifying oils and the like



. distillates. proved entirely unsuccessful, when applied on a large scale or they can only be carried Patented Aug- 1925- UNITED STATES "PATENT OFFICE.

E GON EICHWALD,-OF HAMBURG, GERMANY.

PROCESSIOR PURIEYING OILS AND THE LIKE.

No Drawing.

To all whom it may concern:

Be it known that I, Econ EIcHwALn, residing at Hamburg, Germany, have invented certain new and useful Improvements in and Relating to Processes for Purifying Oils and the like, of which the following is aspecification.

Various means and processes have been proposed for purifying oils and oil-like products for the separation of aromatic substances from the other components of 'mineral and tar oils of different kinds and for the extraction of parafiins from the tar-oil These methods have either out with considerable trouble and at great expense. The latter also applies in the case of the two processes which are based on the use of acetone or of liquid sulphurous acid as solvents for certain components. In both rocesses the work must be carried out at airly low temperatures. Acetone dissolves,-

besides the aromatic com ounds, a considerable portion of the hydi'o-aromatic naphthene-like oils, for instance hexahydro-toluene, resulting in losses. Liquid sulphurous acid must be used in fairly large quantities, the amount being, say, from one to two parts forevery part of raw oil, its use and recovery entailing costly'apparatus and causing difliculties in working. Hence,'there is need for a simple purifyin process of this kind, which can be carried out easily and economically. This is provided for by the process according to the present application.

Furfurol is produced in large quantities as a by-product in the hydrolysis ofcellulose and some suitable way of making use of it has been sought. In the experiments carried out with this object it was found, that furfurol and its derivatives are very suitable for readily obtaining from aliphatic and hydro-aromatic hydro-carbons and their mixtures, phenols, alcohols, asphalts, naphthene acids and sulphur-containing compounds of this kind, tar-forming substances andthe like. The term furfurol derivatives means those derivatives of furfurol which are present as admixtures in furfurol obtained from cellulose, and which perhaps in the future may be obtained in still greater quantities than they are to-day. This led to the process according to the present application, which is described below in connection with three examples.

' Application medium 2, 1923. Serial No. 643,082.

which is not released there Will be about 4% of furfurol, which is recovered by evaporation in vacuo at 80-90. After the furfurol has been distilled off the aromatic oils of the solution may be used for all purposes for which they can otherwise be used.

(2) One part by weight of low temperature tar oil from lignite having a boiling point of 275-300 is treated with one, part by weight of furfurol, as in the first ex-- ample. -About 40% aromatic oils will go into solution. Lignite-low temperature tar OllS contain 40% or moreof aromatic substances, which can be extracted with furfurol or furfurol derivatives. The aliphatic oils, which are separatedpfi', are light coloured and do not become dark-later.

(3) Four parts by weight of a Mexican raw oil having a sulphur content of 2.1% are I treated with onepart by weight of furfurol,

be effected in some cases at a reduced or increasedtemperature by means of furfurol.

I claim:

1. Aprocess for purifying hydrocarbonlike oils or their admixtures, with organic solvents, more particularly for separating the aromatic oil-like substances contained therein from aliphatic and hydro-aromatic oil-like compounds, consisting in adding a quantity of a substancecontaining furfurol to theoils or their admixtures and intimately mixing it therewith,

mixture to stand, and

of the substances containing memes alicwing the separatingthe layer furfuroi from the remaining portion, as endfor the purpose set forth.-

2. A process for purifying hydro-carbon oils or their admixtures With organic s01- vents, consisting in e dding a, quantity of fiurfuroi to the oils or their admixtures and. intimately mixing the furfurol therewith; 10

allowing the mixture to stand, and then sepmating the layer of furfurol from the rema inder of the mixture.

in testimony, Whereofl afix my signature.

EGON EICHWALD. 

